Currency exchange

In three major Canadian cities, you can purchase real bitcoins and use the alternative money to buy your lunch at participating businesses. But Bitcoin isn't the first substitute for government issued currencies.

5: Number of hotels American Express signed up in 1994 to allow travellers to trade frequent flyer points for items other than flights. Diners Club started the trend the previous year by offering meals, savings bonds and consumer goods for miles.

1:1: Effective exchange rate of euros to local Greek alternative currency TEMs. Adopted in 2010 by the austerity-struck town of Volos, near Athens, residents can barter goods, services or labour for the scrip.

1.6: Value in billions of US dollars of the Vancouver-based Ripple cryptocurrency earlier this year. Bitcoin's capitalization amounted to nearly US$8 billion at the same time.

5: Denominations of BerkShare notes, a US-dollar substitute in the Berkshire region of Massachusetts. Available through five banks and accepted by more than 400 businesses, the currency features Norman Rockwell on the 50 BerkShare note.

18: Months the "inflation-proof" currency The Constant circulated from 1972 to 1974. Its value was backed by a global basket of commodities and it was briefly adopted by government agencies and businesses in New Hampshire.

60: Millions of Liberty dollars in circulation after the alternative currency was introduced in 1998. Supporters call its creator, Bernard von NotHaus, "the Rosa Parks of the constitutional currency movement;" the US government calls him a convicted counterfeiter.

123: Article of the Mexican constitution violated by Wal-Mart's Mexican subsidiary when it was found to have illegally paid workers in vouchers redeemable only at its stores.